The invention relates to a method and a system for recognizing routing information on mail items.
When sorting/routing mail items, not all machine-processed mail items can be processed completely automatically. The reasons for this are numerous and range from address units that are not found to contradictions in the read address, which cannot be solved by the equipment. In those cases, the electronic reading devices are forced to stop the processing operation, without being able to provide a final result.
Presently known solutions for an integrated processing of mail items are based on the principle of a 2-stage processing, which functions as follows when simplified.
Stage 1
The scanner provides the electronic reading devices with a non-condensed binary/gray image and attempts to process the mail item completely. In the process, the following steps can be realized.
ROIxe2x80x94recognizing regions of possibly relevant information
Separation of lines in a region
Recognition of characters and word separation
Address interpretation with address analysisxe2x80x94assigning possible meanings to a word
Address correlationxe2x80x94decision for a meaning and determination of the sorting result based on the comparison results with reference data (dictionary)
In the process, alternative meanings are obtained for all processing steps. However, the processing is stopped permanently if no result is achieved in one of the steps or several results are obtained with the same probability, so that no clear meaning can be determined in the end.
The mail item is sent as reject to the machine control, which then issues a command for further processing to the video coding system.
Stage 2
The video-coding system is provided with a condensed binary image at the same time as the electronic reading devices, or following a rejection, and also attempts to process the mail item completely after a command is issued by the machine control. In that case, partial results from the electronic reading device can be taken into account. A uniform coding flow is a necessary precondition, especially with a multi-stage coding of all relevant address components, so as to achieve a high throughput for each coding station. Minimizing the coding expenditure for each mail item by using the partial results is only conditionally possible since the resulting plurality of entry points for the coding interferes with the uniformity. The processing follows the motto:
xe2x80x9cCoding is faster than thinking!xe2x80x9d
Thus, the practice of entering unnecessary information instead of limiting the coding device to the input of the minimally needed information by means of extensive user guidance is taken into account. As a result the online capacity is also restricted owing to the necessary coding time (U.S. Pat. No. 4,632,252).
The mechanical delay loop length in the sorting machine is critical for the separation into online and off-line processing. Basically, 2 different systems are offered.
1. Machines with a short delay loop (approx. 4-5 seconds) process the mail items online only by means of an electronic reading device. The downstream-connected coding system is operated off-line (U.S. Pat. No. 4,992,649).
Machines with longer delay loops can additionally process a portion of the mail items online in the coding system (German Patent 43 24 255).
A further disadvantage is the high demand level on the capabilities of the video coding forces.
The invention is based on the problem definition of reading the routing information on the surface of mail items as quickly as possible using automatic OCR reading devices and video coding stations while making low demands on the video coding forces.
Less is required of the video coding forces, owing to the fact that the automatic OCR processing unit does not stop the image processing following an unclear result in one of the processing steps. Instead, it changes over to a standby condition and a job is generated for a video coding station to provide a clear solution for this step, which includes the information on the operations to be carried out. In addition, the processing speed of the complete reading process increases, so that the share of online processed mail items increases if respective intermediate storage areas exist. Advantageous embodiments of the invention are specified in the dependent claims.
Owing to the fact that the task is displayed on the video coding station monitor and the video coding stations are divided into different job categories according to a feature of the invention, a particularly rapid coding with very low coding requirements results.
According to a further feature, the jobs for the video coding stations are generated advantageously by job formulators, which search for the unclear results/intermediate results in the context memory of the OCR processing unit, then formulate corresponding jobs for a clear solution of these reading problems and transmit these to the video coding stations to be displayed on the monitors.
Further advantageous embodiments provide for response processors, which insert the data from the video coding stations into the context memory, delete unclear results and transmit a signal for continuing the reading process to the OCR processing unit.
It is furthermore advantageous to provide a job distributor at the entrance to the video coding device, which distributes the incoming coding jobs in accordance with task responsibilities stored in a coding station data bank and distributes workload messages from the video coding stations to these. For a particularly fast and effective operating mode, it is advantageous according to claim 10 to install a fast, automatic online routing information reader upstream of the arrangement according to the invention. If this reader does not read the routing information within a predetermined, short time interval, the respective images are forwarded to the arrangement according to the invention.
Finally, it is also advantageous if several images are processed in parallel.
The invention is explained in the following with an exemplary embodiment and with the aid of the drawings.